The present invention generally relates to reinforcing structures for motor vehicles, in particular for commercial vehicles provided with a cab. The invention relates to an impact transferring structure for reinforcing a door of a motor vehicle which more efficiently transfers impact energy to the vehicle frame in the longitudinal direction of the vehicle.
Structural reinforcements are commonly employed within motor vehicle doors to provide an increased level of protection against intrusion into the passenger compartment during a side impact collision. Such structural reinforcements are commonly referred to as “intrusion beams” or “side-impact beams”. Common forms of known intrusion beams range from tubular members which horizontally extend between inner and outer panels of a vehicle door to metal stampings welded to a frame or an inner panel of the door.
One example of a structural reinforcement for a vehicle door is shown in U.S. Pat. No. 7,059,657. This patent describes a supporting frame of high strength steel with side impact guard beam, an outer panel fastened on the frame so that the side impact guard beam will be close to the frame, a beam structure releasably mounted on the frame, and an inner panel fastened on the beam structure, the window structure of the door being mounted on the releasable beam structure and located between the frame and the beam structure. The object of this arrangement is to absorb impact forces in the transverse direction of the vehicle under deformation of the beam.
While the arrangement shown and described in U.S. Pat. No. 7,059,657 and many other prior known arrangements have proven to be commercially acceptable for their intended side-impact applications in automobiles, they are not directly transferable to commercial vehicle. In a commercial vehicle, side impact protection of the type described above is usually not required, due to the height of the drivers cab above ground. Also, in passenger vehicles, impact forces occurring in the longitudinal direction during a frontal collision is commonly absorbed by deformation zones the front structure. In many commercial vehicles there is no front structure of this type that is suitable for use as a deformation zone.
Hence, it is desirable to improve the handling of impact energy in the longitudinal direction in the drivers cab of a commercial vehicle.
It is desirable to provide an apparatus for reinforcing a vehicle door which functions to reduce intrusion into the driver's compartment in the event of a frontal or offset frontal collision.
It is desirable to provide a vehicle door assembly with a reinforcing structure which improves handling of impact energy in the longitudinal direction by transferring impact energy received by the A-pillar to the door through the door hinges and the reinforcing structure to the B-pillar of the vehicle frame.
In the text, the terms “vehicle door” or “vehicle door assembly” relates to a substantially complete door comprising an inner skin panel, an outer skin panel and a door frame, onto which the inner and outer skin panels and a number of accessories are attached. Accessories may comprise component parts such as a hinge assembly, a latching means, a window operating mechanism, etc. The door frame is preferably a pressed sheet metal component that may include a frame surrounding a window opening. The vehicle frame comprises all chassis components surrounding the vehicle door assembly, including the A-pillar extending along the front portion of the door frame and the B-pillar extending along the rear portion of the door frame. References to a relative position, such as “front”, “rear”, “inner” or “outer” are taken relative to a central longitudinal axis through the vehicle in its main direction of travel.
The reinforced door comprises a door frame and a hinge assembly and a latching means. The hinge assembly comprises at least two hinges which pivotally interconnects the door frame and the vehicle frame. The latching means may retain the door frame in a closed position in the vehicle frame. The reinforced door assembly further comprises a reinforcement member extending through the door between the A-pillar and the B-pillar of the vehicle frame. The reinforcement member may have a first end attached to a front portion of the door frame, adjacent or directly to one hinge in the hinge assembly, or alternatively between an upper and a lower hinge making up the hinge assembly. A second end is attached to a rear portion of the door frame adjacent or directly to the latching means.
The motor vehicle may preferably, but not necessarily, be a commercial vehicle, which comprises a cab. The invention is particularly suitable for commercial vehicles of the cab-over type.
In the case of a commercial vehicle, impact energy received by the reinforcing structure during a frontal or offset frontal collision is at least partially transferred to the vehicle frame through the hinge. Frontal collision forces applied to a cab for a commercial vehicle may in some cases cause a twisting deformation of the A-pillar about an axis in its longitudinal extension. The reinforcing structure may assist in preventing this twisting deformation, which deformation may also affect the hinge assembly attached to the A-pillar. As a result, a displacement of the hinges may be prevented or at least reduced, so that the door may be retained in its closed position during the collision event.
According to one embodiment, the invention relates to a reinforcing structure in a vehicle door, which structure is arranged to transfer impact forces in the longitudinal direction of the vehicle. The structure may comprise a first reinforcing member having a longitudinal and vertical extension and being attached to a door frame between a hinge at a front portion of the door frame and a latching means at a rear portion of the door frame. The first reinforcing member may be connected to the door frame by means of welding, soldering or by use of adhesives or mechanical fasteners, such as rivets, screws or nut and bolt connectors.
The structure further comprises a second reinforcing member extending in the longitudinal direction of the vehicle from a front portion of the door frame at or near a hinge to a latching means at a rear portion of the door frame.
The positioning of the ends of the second reinforcing member is preferably selected so that the said ends are terminated at or adjacent a vertical plane at right angles to the longitudinal axis of the vehicle through the respective hinge or latching means. At the same time, the distance between the respective end of the second reinforcing member and its associated hinge or latching means may be varied upwards or downwards in the direction of the said vertical plane, so that the respective end is located at or near its associated hinge or latching means. In this context, “near” may be interpreted as less than half the distance between the hinges.
The second reinforcing member may have a shaped, profiled cross-section and has a greater longitudinal extension than the first reinforcing member, in that each end portion of the second reinforcing member extends beyond the outer limiting edges of the first reinforcing member. Each end portion is used for securing the second reinforcing member to the door frame at or adjacent the hinge and the latching means respectively.
The first reinforcing member and the second reinforcing member are connected to form a structure with a closed cross-section. The said members may be connected by means of welding, soldering or by use of adhesives or mechanical fasteners.
According to one example, the reinforcing structure comprises said interconnected first and second reinforcing members, wherein the second reinforcing member is a beam attached at its ends at the said hinge and at the said latching means. The beam may comprise a single pressed sheet metal component made from high strength steel or a similar suitable material. Each end of the beam may be attached to door frame by means of welding, soldering or by use of adhesives or mechanical fasteners.
According to a second example, the reinforcing structure comprises said interconnected first and second reinforcing members, wherein the second reinforcing member comprises a first section attached to the first reinforcing member and at least one further section attached between the first section and the door frame. Each further section connects the said first section to the door frame at one or both ends thereof. Each said further section may comprise a single pressed sheet metal component, in the form of a bracket, made from high strength steel or a similar suitable material. The thickness of the sheet metal component making up the further section may be equal to or greater than that of the first section.
For instance, the second reinforcing member may comprise a first section attached to the first reinforcing member, a second section attached at the said hinge and to a front portion of the first section, and a third section attached at the said latching means and to a rear portion of the first section. In this way, the first reinforcing member and the said first section of the second reinforcing member, as well as the respective second and third sections and the door frame, are connected to form a continuous structure with a closed cross-section, or box section
Each of the second and third sections may be attached to their respective end of the beam and to the door frame by means of welding, soldering or by use of adhesives or mechanical fasteners.
The first section and the at least one further section preferably comprises mating portions with a profiled cross-section. Preferably, the first section and the at least one further section has the same cross-sectional profile to facilitate assembly of the sections. Preferably, the at least one further section retains its profiled cross-section at least up to its attachment point with the door frame.
As stated above, the first reinforcing member and the second reinforcing member are connected to form a structure with a closed cross-section. In addition, both ends of the second reinforcing member are connected to the door frame to form a structure with a closed cross-section. In this way, the reinforcing structure may be provided with a continuous force transferring structure with a closed cross-section along substantially the entire length of the second reinforcing member to form a box section. The cross-sectional area of the closed cross-section, or box section, may be maximised to improve the force transferring properties of the reinforcing structure. This can be achieved by shaping at least the second reinforcing member to provide it with a suitable cross-sectional shape. The first reinforcing member may also be provided with a shaped cross-sectional profile in the region between its-attachment points or lines of attachment with the second reinforcing member, in order to increase the cross-sectional area of the closed cross-section further.
As indicated above, the reinforcing structure primarily comprises the box section created by the interconnected first and second reinforcing members as well as the interconnected portions of the door frame and the respective ends of the second reinforcing member. In addition, the first reinforcing member is also connected to the door frame along its outer periphery. This arrangement will improve the properties of the reinforcing structure by distributing impact forces to the door frame. In order to achieve this, the first reinforcing member has a vertical extension, or height, equal to or greater than that of the second reinforcing member.
According to one example, the second reinforcing member described above may have a substantially hat-shaped cross-sectional profile. However, the invention is not limited to such a profile. The cross-sectional profile may also vary along the length of the second reinforcing member.
It is desirable to provide a reinforcing structure that distributes impact forces in a substantially straight line between the hinge and the latching means. Hence the longitudinal axis of the second reinforcing member may be arranged parallel to a straight line connecting the hinge and the latching means. Alternatively, the first and second reinforcing members are arranged so that a straight line connecting the hinge and the latching means coincides with the closed cross-section.
The reinforcing structure is preferably arranged between an inner skin panel and a window supporting structure in the vehicle door. The first reinforcing member may be a door module onto which a number of accessories are attached. Accessories may comprise component parts such as a window operating mechanism, audio equipment such as a loudspeaker, etc. The door frame may have a stamped out recess substantially conforming to the general outline of the outer edge of the door module. According to one example, the door module, with or without accessories assembled, may be mounted to the outer surface of the door frame. Subsequently, the second reinforcing member in the form of a single beam is attached to the door module. Depending on the shape of the door frame, the door module may be adapted to have the beam mounted on its inner or its outer surface. The ends of the said beam are then attached at the said hinge and at the said latching means. According to an alternative example, the door module, with or without accessories assembled, may be mounted to the inner surface of the door frame. Subsequently, a first section of the second reinforcing member in the form of a single beam is attached to the door module. Similar to the above example, the door module may be adapted to have the first section mounted on its inner or its outer surface. The ends of the said first section are then attached at the said hinge and at the said latching means by means of a second and third section, or bracket.
The door module may comprise a substantially flat sheet metal component. As described above, the first reinforcing member forming said door module may be provided with local areas formed to contribute to the cross-sectional area of the closed box section when the second reinforcing member is attached. In this example, the first reinforcing member has a vertical extension, or height, greater than that of the second reinforcing member, in order to provide space for predetermined component parts and attachment portions for attaching the first reinforcing member to the door frame.
The invention further relates to a vehicle provided with a reinforcing structure as described above. The vehicle is preferably, but not necessarily, a cab-over type commercial vehicle.
The invention is, as a rule, not intended for reinforcing purposes during a collision with a relatively low passenger vehicle that strikes a front bumper or its associated under-run protection system. The invention is primarily intended for reinforcing purposes during collisions with vehicles such as SUV's, trucks or buses, or if the front portion of the cab is impacted by an object in the region of the cab above the bumper, where impact forces may affect the A-pillar of the cab.
Additional advantages of the present invention will be described in the subsequent description of the preferred embodiments and the appended claims, in combination with the appended drawings.